This is from an old post :
Author: Tom Ross (165.112.78.---)
Date: 10-13-04 09:18
Try using it with the -retrend option. 3dFourier removes a linear trend in the data prior to filtering; -retrend returns it. Without a mean to the timecourses, EPI data look like random pixelated garbage. I'm not sure about the 'looking off center', but would bet it will be fixed as well.
Tom